No, detailed sexual questions to today’s degree have not been part of the history of American policing.
And this is not in an interview, it is in the polygraph process.
Refuse to answer there and the polygrapher will report you as non-cooperative (deceptive) and you are out of the process.
No one should have to discuss their sexual activities in detail for employment. Especially when it involves their wife or husband. if it isn’t cause for firing, it isn’t relevant.
Ah, polygraph questions. Anyone in their right mind would just refuse to be polygraphed just on principle. Bogus, often wrong, easily fooled.